Bio potential signals monitoring in biomedical field add more precise way of handling human/nonhuman signals. Operational Amplifier plays a key role in Analog circuits of which biomedical application is the key area. We have opted for a CMOS (Complementary Metal oxide Semiconductor) design with fully differential Operational Amplifier having CMFB (Common Mode Feedback) circuit to decrease the noise content present in Bio potential signals measured. Bio potential signals are low frequency, low amplitude range signals. Hence the noise present in the Operational Amplifier is flicker noise at low frequency it dominates other frequencies, hence effectively filtering out the flicker frequency components forms the crux in noise removal. The fully differential Operational Amplifier is drawn from single differential Operational Amplifier to get low noise levels. The beauty of our project lies in the modified architecture of Operational Amplifier. The circuit with fully differential Operational Amplifier and CMFB helps in scaling down of noise to 0.34nv/√Hz at corner frequency of 10 Hz with 1v of power supply which performed better than the Fully Differential Operational Amplifier [1]. The Modified design in this paper has been implemented in Cadence 90nm technology. © Research India Publications.